UV protection compositions

ABSTRACT

The present invention relates to compositions suitable for providing protection against the harmful effects of ultraviolet radiation. The compositions provide excellent efficiency, broad spectrum UV efficacy, and photostability. Methods of use for these compositions are also disclosed. The present compositions comprise: a) an effective amount of a UVA-absorbing dibenzoylmethane sunscreen active; 
     b) an and effective amount of a naphthalene derivative having the formula ##STR1##  wherein R is in the 1 or 2 position and is independently selected from the group consisting of CHO, COOH, COR&#39; wherein R&#39; is a C 1  -C 30  straight or branched alkyl or an aryl, and wherein said naphthalene derivative has a triplet energy state of from about 56 kcal/mol to about 59.5 kcal/mol; and 
     c) a suitable carrier.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation-In-Part of application Ser. No.09/174,225 filed Oct. 16, 1998 now abandoned.

TECHNICAL FIELD

The present invention relates to compositions suitable for providingprotection against the harmful effects of ultraviolet radiation havingexcellent efficiency, broad spectrum UV efficacy, and photostability.The compositions comprise a UVA-absorbing dibenzoylmethane sunscreenactive, a naphthalene derivative having a triplet energy state fromabout 56 kcal/mol to about 59.5 kcal/mol, and a suitable carrier.

BACKGROUND OF THE INVENTION

It is well known that exposure to sunlight can pose a number of hazardsto the skin. These damaging effects may result not only from sunbathingbut also from the sunlight exposure associated with daily outdooractivities. The major short term hazard of prolonged exposure tosunlight is erythema, i.e., sunburn, which primarily results from UVBradiation having a wavelength of from about 290 nm to about 320 nm. Overthe long term, however, malignant changes in the skin surface oftenoccur. Numerous epideminologic studies demonstrate a strong relationshipbetween sunlight exposure and human skin cancer. Another long termhazard of ultraviolet radiation is premature aging of the skin, which isprimarily caused by UVA radiation having a wavelength of from about 320nm to about 400 nm. This condition is characterized by wrinkling andpigment changes of the skin, along with other physical changes such ascracking, telangiectasis, solar dermatoses, ecchymoses, and loss ofelasticity. The adverse effects associated with exposure to UV radiationare more fully discussed in DeSimone, "Sunscreen and Suntan Products,"Handbook of Nonprescription Drugs, 7th Ed., Chapter 26, pp. 499-511(American Pharmaceutical Association, Washington, D.C.; 1982); Grove andForbes, "A Method for Evaluating the Photoprotection Action of SunscreenAgents Against UV-A Radiation," International Journal of CosmeticScience, 4, pp. 15-24 (1982); and U.S. Pat. No. 4,387,089, DePolo,issued Jun. 7, 1983.

As a result of the abovementioned hazards associated with sunlightexposure, the general public's interest in the sun protection productmarket has grown considerably. Today, there are not only sunscreenproducts for sunbathing but there are also a variety of personal careproducts containing sunscreens, particularly cosmetic type productswhich are worn daily. "Personal care products" refer to health andcosmetic beauty aid products generally recognized as being formulatedfor beautifying and grooming the skin and hair. For example, personalcare products include sunscreen products (e.g., lotions, skin creams,etc.), cosmetics, toiletries, and over-the-counter pharmaceuticalproducts intended for topical usage.

Many conventional sunscreen products, in particular, are deficient,however, due to their inability to provide efficacious protectionagainst broad spectrum UV radiation, i.e., protection against both UVBand UVA radiation. Today, most commercially available sunscreen productsare efficient at absorbing UV radiation in the 290 nm to 320 nm UVBregion such that sunburn of the skin is prevented. They are lessefficient when it comes to absorbing light which falls in the 320 nm to400 nm UVA region, which leaves the skin vulnerable to premature skinaging. This deficiency is due in part to the limited number of UVAabsorbing sunscreen actives which are both commercially available andapproved for global use. One class of these sunscreen actives includesdibenzoylmethane compounds which provide broad spectrum UV protectionand 4-tert-butyl-4'-methoxydibenzoylmethane, in particular, is alsoapproved for global use. Unfortunately, these sunscreens tend tophotodegrade upon exposure to UV radiation thereby reducing their UVAefficacy. Consequently, sunscreen products which include these compoundsare typically more difficult to formulate due to the inherent lack ofphotostability of dibenzoylmethane compounds. One approach to stabilizethese types of sunscreens is described in U.S. Ser. No. 07/929,612,Deckner, filed Aug. 13, 1992, involving the use of benzylidene camphorsunscreens to stabilize the dibenzoylmethane compound. Suchcompositions, however, are not currently approved for global use onhumans.

Thus, there is a need for photostabilized compositions suitable forproviding protection against the harmful effects of UV radiation tohuman skin. In particular, in the personal care industry, a need remainsfor sunscreen products having excellent photostability, efficiency, andwhich provide broad spectrum UV protection (i.e., against both UVA andUVB radiation) in a safe and economical manner.

Likewise, in other industries such as the automotive care, marinevehicle care, household care, animal care, and coatings industries, UVradiation causes undesirable wear and damage. Therefore, a need existsfor photostabilized compositions suitable for providing protectionagainst the harmful effects of UV radiation to a variety of objectsand/or materials prone to sun exposure.

It has surprisingly now been found that the compositions of the presentinvention, which comprise a UVA-absorbing dibenzoylmethane sunscreenactive, a naphthalene derivative, and a suitable carrier, provideexcellent photostability, efficiency, and UV protection efficacy(including both UVA and UVB protection), in a safe and economicalmanner.

SUMMARY OF THE INVENTION

The present invention relates to a composition suitable for providingprotection against the harmful effects of ultraviolet radiationcomprising:

a) an effective amount of a UVA-absorbing dibenzoylmethane sunscreenactive;

b) an effective amount of a naphthalene derivative having the formula##STR2## wherein R is in the 1 or 2 position and is independentlyselected from the group consisting of CHO, COOH, COR' wherein R' is a C₁-C₃₀ straight or branched alkyl or an aryl, and wherein said naphthalenederivative has a triplet energy state of from about 56 kcal/mol to about59.5 kcal/mol; and

c) a suitable carrier.

In preferred embodiments, the UVA-absorbing dibenzoylmethane sunscreenactive and the naphthalene derivative are present in "safe andeffective" amounts and the mole ratio of the UVA-absorbingdibenzoylmethane sunscreen active to the naphthalene derivative is fromabout 8:1 to about 1:1, more preferably from about 4:1 to about 1:1, andmost preferably from about 2:1 to about 1:1. The present invention alsorelates to methods for providing protection to skin from the harmfuleffects of UV radiation by topical application of such compositions.Furthermore, the present invention relates to methods of stabilizing aUVA-absorbing dibenzoylmethane sunscreen active.

DETAILED DESCRIPTION OF THE INVENTION

The compositions of the present invention are useful for providingprotection against the harmful effects of ultraviolet radiation,especially to human skin. The essential components of these compositionsare described below. Also included is a nonexclusive description ofvarious optional and preferred components useful in embodiments of thepresent invention.

The present invention can comprise, consist of, or consist essentiallyof any of the required or optional ingredients and/or limitationsdescribed herein.

All percentages and ratios are calculated on a weight basis unlessotherwise indicated. All percentages are calculated based upon the totalcomposition unless otherwise indicated.

All molar weights are weight average molecular weights and are given inunits of grams per mole.

All ingredient levels are in reference to the active level of thatingredient, and are exclusive of solvents, by-products, or otherimpurities that may be present in commercially available sources, unlessotherwise indicated.

All measurements made are at ambient room temperature, which isapproximately 73° F., unless otherwise designated.

All documents referred to herein, including patents, patentapplications, and printed publications, are hereby incorporated byreference in their entirety in this disclosure.

By "safe and effective amount" is meant an amount of a compound,component, or composition (as applicable) sufficient to significantlyinduce a positive effect (e.g., photoprotection or improvement inphotostability), but low enough to avoid serious side effects, (e.g.,undue toxicity or allergic reaction), i.e., to provide a reasonablebenefit to risk ratio, within the scope of sound medical judgment.

By "effective amount" is meant an amount of a compound, component, orcomposition (as applicable) sufficient to significantly induce apositive effect (e.g., photoprotection or improvement inphotostability).

UVA-Absorbing Dibenzoylmethane Sunscreen Active

The compositions of the present invention comprise a UVA-absorbingdibenzoylmethane sunscreen active which absorbs UV radiation having awavelength of from about 320 nm to about 400 nm. Preferred UVA-absorbingdibenzoylmethane sunscreen actives have the general structure ##STR3##wherein R₁ is a substituent selected from the group consisting of H, OR,and NRR wherein each R is independently H, or C₁ -C₂₀ straight orbranched alkyls, R₂ is selected from the group consisting of H or OH,and R₃ is selected from the group consisting of H, or C₁ -C₂₀ straightor branched alkyls. Even though the dibenzoylmethane chromophore isrepresented as a 1,3-diketone, it should be understood that thisrepresentation in no way excludes other tautomeric forms of thefunctional group such as the enol form. Thus, whenever the 1,3-diketoneform is designated, it is understood that all appropriate enol tautomersare also contemplated and included herein. These tautomeric enol formsof the dibenzoylmethane chromophore can be represented by the followingtautomeric structures. ##STR4## wherein R₁, R₂, and R₃ are defined asabove. Examples of such UVA-absorbing dibenzoylmethane sunscreen activesare described in U.S. Pat. No. 4,489,057, issued to Welters et al. onDec. 18, 1984 and U.S. Pat. No. 4,387,089, issued to Depolo on Jun. 7,1983; and in Sunscreens: Development, Evaluation, and RegulatoryAspects, edited by N. J. Lowe and N. A. Shaath, Marcel Dekker, Inc.(1990).

Suitable UVA-absorbing dibenzoylmethane sunscreen actives include, butare not limited to, those selected from the group consisting of2-methyldibenzoylmethane, 4-methyldibenzoylmethane,4-isopropyldibenzoylmethane, 4-tert-butyldibenzoylmethane,2,4-dimethyldibenzoylmethane, 2,5-dimethyldibenzoylmethane,4,4'-diisopropylbenzoylmethane, 4-tert-butyl-4'-methoxydibenzoylmethane,2-methyl-5-isopropyl-4'-methoxydibenzoylmethane,2-methyl-5-tert-butyl-4'-methoxydibenzoylmethane,2,4-dimethyl-4'-methoxydibenzoylmethane,2,6-dimethyl-4'tert-butyl-4'methoxydibenzoylmethane, and mixturesthereof. Preferred UVA-absorbing dibenzoylmethane sunscreen activesinclude those selected from the group consisting of4-tert-butyl-4'-methoxydibenzoylmethane, isopropyldibenzoylmethane, andmixtures thereof. A more preferred UVA-absorbing dibenzoylmethanesunscreen active is 4-tert-butyl-4'-methoxydibenzoylmethane.

The sunscreen active, 4-tert-butyl-4'-methoxydibenzoylmethane, which isalso known as butyl methoxydibenzoylmethane or Avobenzone, iscommercially available under the names Parsol® 1789 from Givaudan-Roure(International) S.A. (Basel, Switzerland) and Eusolex® 9020 from Merck &Co., Inc. (Whitehouse Station, N.J.). The sunscreen4-isopropyldibenzoylmethane, which is also known as isopropyldibenzoylmethane, is commercially available from Merck under the nameEusolex 8020.

The UVA-absorbing dibenzoylmethane sunscreen active of the instantinvention is present in an effective amount, preferably in a safe andeffective amount, to provide broad spectrum UV protection eitherindependently or in combination with other UV protective actives whichmay be present in the composition. The composition preferably containsfrom about 0.01% to about 30%, more preferably from about 0.1% to about6%, and most preferably from about 1% to about 3%, by weight of thecomposition, of the UVA-absorbing dibenzoylmethane sunscreen active.Exact amounts of the sunscreen active will vary depending upon thedesired Sun Protection Factor, i.e., the "SPF" of the composition aswell as the desired level of UVA protection. (SPF is a commonly usedmeasure of photoprotection of a sunscreen against erythema. The SPF isdefined as the ratio of the ultraviolet energy required to produceminimal erythema on protected skin to that required to produce the sameminimal erythema on unprotected skin in the same individual. See FederalRegister, 43, No. 166, pp. 38206-38269, Aug. 25, 1978).

Naphthalene Derivative

The compositions of the present invention also comprise a naphthalenederivative having the formula ##STR5## wherein R is in the 1 or 2position and is independently selected from the group consisting of CHO,COOH, COR' wherein R' is a C₁ -C₃₀ straight or branched alkyl or aryl,and wherein said naphthalene derivative has a triplet energy state offrom about 56 kcal/mol to about 59.5 kcal/mol.

As used herein, "alkyl" means carbon-containing chains which may bestraight, branched or cyclic; substituted or unsubstituted; saturated,monounsaturated (i.e. one double or triple bond in the carbon chain), orpolyunsaturated (i.e. two or more double bonds in the carbon chain, twoor more triple bonds in the carbon chain, one or more double and one ormore triple bonds in the carbon chain). Unless otherwise indicated,alkyl are preferably as follows. Preferred alkyl are straight orbranched chain, more preferably straight chain. Preferred alkyl aremono-, di-, or tri-substituted, or unsubstituted, most preferablyunsubstituted. Preferred alkyl are saturated or monounsaturated and, ifso, preferably with a double bond; more preferably alkyl are saturated.Preferred alkyls are C₁ -C₃₀, more preferably C₁ -C₁₀, also morepreferably C₁ -C₄, even more preferably methyl, ethyl and t-butyl, evenstill more preferably methyl and ethyl, and most preferably methyl.

Thus the term "substituted alkyl" is included in the definition ofalkyl. Preferred alkyl substituents (i.e. substitution on alkyls)include ester, ketone, aldehyde, carboxylic acid, halo, aryl, amino,hydroxy, alkoxy, cyano, nitro, amino (including mono- and disubstitutedamino), thiol, and substituted thiol and trifluoromethyl. More preferredalkyl substituents are ester and aryl.

As used herein the term "alkoxy" includes the above described alkylradicals attached to the molecule via oxygen. Thus, alkyl not onlyincludes the C₁ -C₁₀ alkoxy, but also includes species such asmethylenedioxy, ethylenedioxy and other similarly bifunctional, ormultifunctional alkoxy substituents. These multifunctional substituentscan be attached to various places in the molecule and thus form bridgedspecies. For example, species such as dioxolanes, dioxanes and the likeare specifically contemplated.

As used herein "halo" means F, Cl, Br, and I. Preferred "halos" are F,Cl, and Br, more preferably F and Cl, most preferably F.

As used herein, "aryl" means aromatic rings which may be unsubstitutedor substituted. Preferred aryl are phenyl or naphthyl, especiallyphenyl. Preferred aryl are mono-, di-, tri-substituted or unsubstituted;more preferred aryl are monosubstituted or unsubstituted, most preferredbeing unsubstituted. Preferred aryl substituents include ester, ketone,aldehyde, carboxylic acid, alkyl, halo, amino, hydroxy, alkoxy, cyano,nitro and trifluoromethyl. More preferred aryl substituents are alkyland ester. The most preferred aryl is unsubstituted and thus is phenyl.

Triplet energy levels may be determined via phosphorescence or oxygenperturbation techniques as described by J. Gonzenbach, T. J. Hill, andT. G. Truscott in "The Triplet Energy Levels of UVA and UVB Sunscreens",J. Photochem. Photobiol. B: Biol., vol. 16, pp.377-379 (1992), which isincorporated by reference herein in its entirety. The oxygenperturbation technique involves measuring the UV absorption spectrum ofa compound while that compound is under an oxygen enhanced high pressureenvironment, e.g., 2000 psi. Under these conditions, spin selectionrules break down and exposure of the compound to UV generates the lowestexcited triplet state directly from the ground state. The wavelength, λ(in μm), at which this transition occurs is used to calculate the energyof the triplet (triplet energy level) in kcal/mol using the relationshipof E=28.635/λ which is derived from the equation E=hν wherein E isenergy, h is Planck's constant, and ν is the frequency of theelectromagnetic radiation.

The phosphorescence technique focuses on the fact that many compoundsphosphoresce when UV generated excited triplets decay. By measuring thewavelength at which phosphorescence occurs, the triplet energy level maybe calculated as described above. Triplet energy levels may bedetermined by measuring phosphorescence spectra of test samples with aUV spectrophotometer which is equipped with a phosphorescenceattachment. Such triplet energy levels have been widely reported, e.g.,see A. J. Gordon, R. A. Ford, "The Chemist's Companion," John Wiley &Sons, pp. 351-355 (1972), which is incorporated by reference herein inits entirety.

Preferably, the naphthalene derivative is selected from the groupconsisting of: ##STR6## and mixtures thereof. More preferably, thenaphthalene derivative is selected from the group consisting of1-naphthaldehyde, 1-acetonaphthone, and mixtures thereof. Mostpreferably, the naphthalene derivative is 1-acetonaphthone. Suitablenaphthalene derivatives are commercially available from Aldrich ChemicalCo., Inc. (Milwaukee, Wis.).

The naphthalene derivative improves the photostability of thedibenzoylmethane sunscreen active and of the compositions of the presentinvention. The naphthalene derivative of the present invention ispresent in an effective amount, preferably in a safe and effectiveamount, to reduce the photodegradation of the UVA-absorbingdibenzoylmethane sunscreen active. Photodegradation refers to theappreciable breakdown of a compound upon exposure to UV radiation.Photodegradation may be determined by a reduction of the UV absorptioncapability which in turn may be measured by using standard UV absorptionmethods. Preferred compositions retain at least about 75%, morepreferably at least about 85%, and most preferably at least about 95%,of their initial UV absorption after irradiation with approximately 2J/cm² per desired SPF unit of broad band UV radiation, e.g., 30 J/cm²for an SPF 15 composition. Preferably, the naphthalene derivative ispresent in an amount such that the mole ratio of the UVA-absorbingdibenzoylmethane sunscreen active to the naphthalene derivative is fromabout 8:1 to about 1:1, more preferably from about 4:1 to about 1:1, andmost preferably from about 2:1 to about 1:1.

Carrier

The compositions of the present invention comprise a suitable carrier orvehicle for the UVA-absorbing dibenzoylmethane sunscreen active, thenaphthalene derivative, and any optional components. Suitable carriersare well known in the art and are selected based on the end useapplication. For example, carriers of the present invention include, butare not limited to, those suitable for application to skin, hair, nails,animal skin, fur, automobiles, fabrics, marine vehicles, as well asthose suitable for incorporation into plastics, metals, etc..Preferably, the carriers of the present invention are suitable forapplication to skin (e.g., sunscreens, creams, milks, lotions, masks,serums, etc.); hair and fur (e.g., shampoos, hair setting or treatmentgels or lotions, shaping/curling/fixation lacquers or lotions, etc,);and nails (e.g., polishes, treatments, etc.). In preferred embodiments,the carrier is suitable for application to skin which means that thecarrier and its components are suitable for use in contact with skin,hair, fur, and nails without undue toxicity, incompatibility,instability, allergic response, and the like within the scope of soundmedical judgment. Such carriers are well-known to one of ordinary skillin the art, and can include one or more compatible liquid or solidfiller diluents or vehicles which are suitable for application to skin,hair, fur, and nails. The exact amount of carrier will depend upon thelevel of the UVA-absorbing dibenzoylmethane sunscreen active, thenaphthalene derivative and any other optional ingredients which one ofordinary skill in the art would classify as distinct from the carrier(e.g., other active components). The compositions of the presentinvention preferably comprise from about 20% to about 99.8%, morepreferably from about 50% to about 99%, and most preferably from 75% toabout 95%, by weight of the composition, of a carrier.

The carrier and compositions herein can be formulated in a number ofways, including but not limited to emulsions (in emulsion technology, acomposition comprising a "dispersed phase" and a "continuous phase;" thedispersed phase existing as small particles or droplets that aresuspended in and surrounded by a continuous phase). For example,suitable emulsions include oil-in-water, water-in-oil,water-in-oil-in-water, oil-in-water-in-oil, and oil-in-water-in-siliconeemulsions. Preferred compositions comprise an oil-in-water emulsion.

The compositions of the present invention can be formulated into a widevariety of product types, including creams, waxes, pastes, lotions,milks, mousses, gels, oils, tonics, and sprays. Preferred compositionsare formulated into lotions, creams, gels, and sprays. These productforms may be used for a number of applications, including, but notlimited to, hand and body lotions, cold creams, facial moisturizers,anti-acne preparations, topical analgesics, make-ups/cosmetics includingfoundations, eyeshadows, lipsticks, and the like as well as coatings(e.g., paints, varnishes, polishes, adhesives, etc.), household careitems (e.g., detergents, cleansers, fabric conditioners, etc.),automotive and marine vehicle care items (e.g., waxes, etc.), hair careand styling products (e.g., shampoos, conditioners, gels, mousses,sprays, etc.), topical animal care items (e.g., shampoos, conditioners,skin treatments, etc.). Any additional components required to formulatesuch products vary with product type and can be routinely chosen by oneskilled in the art.

If compositions of the present invention are formulated as an aerosoland applied to the skin as a spray-on product, a propellant is added tothe composition. Examples of suitable propellants includechlorofluorinated lower molecular weight hydrocarbons. A more completedisclosure of propellants useful herein can be found in Sagarin,Cosmetics Science and Technology, 2nd Edition, Vol. 2, pp. 443-465(1972).

Optional Components

The compositions of the present invention may contain a variety of otheringredients such as are conventionally used in a given product typeprovided that they do not unacceptably alter the benefits of theinvention.

In a preferred embodiment, where the composition is to be in contactwith human skin, the optional components should be suitable forapplication to skin, that is, when incorporated into the compositionthey are suitable for use in contact with human skin without unduetoxicity, incompatibility, instability, allergic response, and the likewithin the scope of sound medical judgment. The CTFA Cosmetic IngredientHandbook, Second Edition (1992) describes a wide variety of nonlimitingcosmetic and pharmaceutical ingredients commonly used in the skin careindustry, which are suitable for use in the compositions of the presentinvention. Examples of these ingredient classes include: abrasives,absorbents, aesthetic components such as fragrances, pigments,colorings/colorants, essential oils, skin sensates, astringents, etc.(e.g., clove oil, menthol, camphor, eucalyptus oil, eugenol, menthyllactate, witch hazel distillate), anti-acne agents, anti-caking agents,antifoaming agents, antimicrobial agents (e.g., iodopropylbutylcarbamate), antioxidants, binders, biological additives, bufferingagents, bulking agents, chelating agents, chemical additives, colorants,cosmetic astringents, cosmetic biocides, denaturants, drug astringents,external analgesics, film formers or materials, e.g., polymers, foraiding the film-forming properties and substantivity of the composition(e.g., copolymer of eicosene and vinyl pyrrolidone), opacifying agents,pH adjusters, propellants, reducing agents, sequestrants, skin bleachingand lightening agents (e.g., hydroquinone, kojic acid, ascorbic acid,magnesium ascorbyl phosphate, ascorbyl glucosamine), skin-conditioningagents (e.g., humectants, including miscellaneous and occlusive), skinsoothing and/or healing agents (e.g., panthenol and derivatives (e.g.,ethyl panthenol), aloe vera, pantothenic acid and its derivatives,allantoin, bisabolol, and dipotassium glycyrrhizinate), skin treatingagents, thickeners, and vitamins and derivatives thereof.

The compositions of the present invention may contain one or more ofsuch optional components. Preferred compositions optionally contain oneor more materials selected from UVB sunscreen actives, anti-acneactives, vitamin compounds, skin treating agents, humectants,moisturizers, skin conditioners, thickening agents, structuring agents,and emulsifiers.

In any embodiment of the present invention, however, the actives usefulherein can be categorized by the benefit they provide or by theirpostulated mode of action. However, it is to be understood that theactives useful herein can in some instances provide more than onebenefit or operate via more than one mode of action. Therefore,classifications herein are made for the sake of convenience and are notintended to limit the active to that particular application orapplications listed.

a) UVB Sunscreen Active

The compositions of the present invention may comprise one or more UVBsunscreen actives which absorb UV radiation having a wavelength of fromabout 290 nm to about 320 nm. As used herein the UVB sunscreen activemeans an active other than the UVA-absorbing dibenzoylmethane sunscreenactive which itself may possess UVB absorption properties. Thecompositions comprise an amount of the UVB sunscreen active which issafe and effective to provide UVB protection either independently or incombination with other UV protective actives which may be present in thecomposition, preferably from about 0.1% to about 30%, more preferablyfrom about 0.5% to about 25%, and most preferably from about 1% to about20% by weight of the composition.

A wide variety of UVB sunscreen actives, including both organicsunscreen actives and inorganic physical sunblocks, are suitable for useherein. Nonlimiting examples of such sunscreen actives are described inU.S. Pat. No. 5,087,445 issued Feb. 11, 1992 to Haffey et al; and U.S.Pat. Nos. 5,073,371 and 5,073,372, both issued on Dec. 17, 1991 toTurner et al Nonlimiting examples of suitable physical sunblocks aredescribed in CTFA International Cosmetic Ingredient Dictionary, SixthEdition, 1995, pp. 1026-28 and 1103.

Preferred UVB sunscreen actives are selected from the group consistingof 2-phenyl-benzimidazole-5-sulfonic acid, octyl methoxycinnamate, TEAsalicylate, octyl salicylate, octyl dimethyl PABA, zinc oxide, titaniumdioxide, and mixtures thereof. A preferred water-soluble organicsunscreen active is 2-phenyl-benzimidazole-5-sulfonic acid whilepreferred inorganic physical sunblocks are zinc oxide, titanium dioxide,and mixtures thereof. Salt and acid-neutralized forms of the acidicsunscreens are also useful herein.

b) Anti-Acne Actives

The compositions of the present invention may comprise one or moreanti-acne actives. Examples of useful anti-acne actives includeresorcinol, sulfur, salicylic acid, erythromycin, zinc, etc. Furtherexamples of suitable anti-acne actives are described in further detailin U.S. Pat. No. 5,607,980, issued to McAtee et al, on Mar. 4, 1997.

c) Vitamin Compounds

The compositions of the present invention may comprise vitamincompounds, precursors, and derivatives thereof. These vitamin compoundsmay be in either natural or synthetic form. Suitable vitamin compoundsinclude, but are not limited to, Vitamin A (e.g., beta carotene,retinoic acid, retinol, retinoids, retinyl palmitate, retinylproprionate, etc.), Vitamin B (e.g., niacin, niacinamide, riboflavin,pantothenic acid, etc.), Vitamin C (e.g., ascorbic acid, etc.), VitaminD (e.g., ergosterol, ergocalciferol, cholecalciferol, etc.), Vitamin E(e.g., tocopherol acetate, etc.), and Vitamin K (e.g., phytonadione,menadione, phthiocol, etc.) compounds.

In particular, the compositions of the present invention may comprise asafe and effective amount of a vitamin B₃ compound. Vitamin B₃ compoundsare particularly useful for regulating skin condition as described inco-pending U.S. application Ser. No. 08/834,010, filed Apr. 11, 1997(corresponding to international publication WO 97/39733 A1, publishedOct. 30, 1997) which is incorporated by reference herein in itsentirety. The compositions of the present invention preferably comprisefrom about 0.01% to about 50%, more preferably from about 0.1% to about10%, even more preferably from about 0.5% to about 10%, and still morepreferably from about 1% to about 5%, most preferably from about 2% toabout 5%, of the vitamin B₃ compound.

As used herein, "vitamin B₃ compound" means a compound having theformula: ##STR7## wherein R is --CONH₂ (i.e., niacinamide), --COOH(i.e., nicotinic acid) or --CH₂ OH (i.e., nicotinyl alcohol);derivatives thereof; and salts of any of the foregoing.

Exemplary derivatives of the foregoing vitamin B₃ compounds includenicotinic acid esters, including non-vasodilating esters of nicotinicacid, nicotinyl amino acids, nicotinyl alcohol esters of carboxylicacids, nicotinic acid N-oxide and niacinamide N-oxide.

Examples of suitable vitamin B₃ compounds are well known in the art andare commercially available from a number of sources, e.g., the SigmaChemical Company (St. Louis, Mo.); ICN Biomedicals, Inc. (Irvin, Calif.)and Aldrich Chemical Company (Milwaukee, Wis.).

The vitamin compounds may be included as the substantially purematerial, or as an extract obtained by suitable physical and/or chemicalisolation from natural (e.g., plant) sources.

d) Skin Treating Agent

The compositions of the present invention may contain one or more skintreating agents. Suitable skin treating agents include those effectivefor preventing, retarding, arresting, and/or reversing skin wrinkles.Examples of suitable skin treating agents include, but are not limitedto, alpha-hydroxy acids such as lactic acid and glycolic acid andbeta-hydroxy acids such as salicylic acid.

e) Structuring Agent

The compositions of the present invention may contain a structuringagent such as are known in the art. Structuring agents are particularlypreferred in the oil-in-water emulsions of the present invention.Without being limited by theory, it is believed that the structuringagent assists in providing rheological characteristics to thecomposition which contribute to the stability of the composition. Forexample, the structuring agent tends to assist in the formation of theliquid crystalline gel network structures. The structuring agent mayalso function as an emulsifier or surfactant. Preferred compositions ofthis invention comprise from about 0.5% to about 20%, more preferablyfrom about 1% to about 10%, most preferably from about 1% to about 5%,of one or more structuring agents.

The preferred structuring agents of the present invention are selectedfrom the group consisting of stearic acid, palmitic acid, stearylalcohol, cetyl alcohol, behenyl alcohol, stearic acid, palmitic acid,the polyethylene glycol ether of stearyl alcohol having an average ofabout 1 to about 21 ethylene oxide units, the polyethylene glycol etherof cetyl alcohol having an average of about 1 to about 5 ethylene oxideunits, and mixtures thereof. More preferred structuring agents of thepresent invention are selected from the group consisting of stearylalcohol, cetyl alcohol, behenyl alcohol, the polyethylene glycol etherof stearyl alcohol having an average of about 2 ethylene oxide units(steareth-2), the polyethylene glycol ether of stearyl alcohol having anaverage of about 21 ethylene oxide units (steareth-21), the polyethyleneglycol ether of cetyl alcohol having an average of about 2 ethyleneoxide units, and mixtures thereof. Even more preferred structuringagents are selected from the group consisting of stearic acid, palmiticacid, stearyl alcohol, cetyl alcohol, behenyl alcohol, steareth-2,steareth-21, and mixtures thereof.

f) Thickening Agent (Including Thickeners and Gelling Agents)

The compositions of the present invention can comprise one or morethickening agents, preferably from about 0.1% to about 5%, morepreferably from about 0.1% to about 3%, and most preferably from about0.25% to about 2%, by weight of the composition.

Nonlimiting classes of thickening agents include those selected from thegroup consisting of:

(i) Carboxylic Acid Polymers

These polymers are crosslinked compounds containing one or more monomersderived from acrylic acid, substituted acrylic acids, and salts andesters of these acrylic acids and the substituted acrylic acids, whereinthe crosslinking agent contains two or more carbon-carbon double bondsand is derived from a polyhydric alcohol. Polymers useful in the presentinvention are more fully described in U.S. Pat. No. 5,087,445, to Haffeyet al, issued Feb. 11, 1992; U.S. Pat. No. 4,509,949, to Huang et al,issued Apr. 5, 1985; U.S. Pat. No. 2,798,053, to Brown, issued Jul. 2,1957; and in CTFA International Cosmetic Ingredient Dictionary, FourthEdition, 1991, pp. 12 and 80.

Examples of commercially available carboxylic acid polymers usefulherein include the carbomers, which are homopolymers of acrylic acidcrosslinked with allyl ethers of sucrose or pentaerytritol. Thecarbomers are available as the Carbopol® 900 series from B.F. Goodrich(e.g., Carbopol® 954). In addition, other suitable carboxylic acidpolymeric agents include copolymers of C₁₀₋₃₀ alkyl acrylates with oneor more monomers of acrylic acid, methacrylic acid, or one of theirshort chain (i.e., C₁₋₄ alcohol) esters, wherein the crosslinking agentis an allyl ether of sucrose or pentaerytritol. These copolymers areknown as acrylates/C₁₀₋₃₀ alkyl acrylate crosspolymers and arecommercially available as Carbopol® 1342, Carbopol® 1382, Pemulen TR-1,and Pemulen TR-2, from B.F. Goodrich. In other words, examples ofcarboxylic acid polymer thickeners useful herein are those selected fromthe group consisting of carbomers, acrylates/C₁₀ -C₃₀ alkyl acrylatecrosspolymers, and mixtures thereof.

(ii) Crosslinked Polyacrylate Polymers

The compositions of the present invention can optionally comprisecrosslinked polyacrylate polymers useful as thickeners or gelling agentsincluding both cationic and nonionic polymers, with the cationics beinggenerally preferred. Examples of useful crosslinked nonionicpolyacrylate polymers and crosslinked cationic polyacrylate polymers arethose described in U.S. Pat. No. 5,100,660, to Hawe et al, issued Mar.31, 1992; U.S. Pat. No. 4,849,484, to Heard, issued Jul. 18, 1989; U.S.Pat. No. 4,835,206, to Farrar et al, issued May 30, 1989; U.S. Pat. No.4,628,078 to Glover et al issued Dec. 9, 1986; U.S. Pat. No. 4,599,379to Flesher et al issued Jul. 8, 1986; and EP 228,868, to Farrar et al,published Jul. 15, 1987.

(iii) Polyacrylamide Polymers

The compositions of the present invention can optionally comprisepolyacrylamide polymers, especially nonionic polyacrylamide polymersincluding substituted branched or unbranched polymers. Most preferredamong these polyacrylamide polymers is the nonionic polymer given theCTFA designation polyacrylamide and isoparaffin and laureth-7, availableunder the Tradename Sepigel 305 from Seppic Corporation (Fairfield,N.J.).

Other polyacrylamide polymers useful herein include multi-blockcopolymers of acrylamides and substituted acrylamides with acrylic acidsand substituted acrylic acids. Commercially available examples of thesemulti-block copolymers include Hypan SR150H, SS500V, SS500W, SSSA100H,from Lipo Chemicals, Inc., (Patterson, N.J.).

(iv) Polysaccharides

A wide variety of polysaccharides are useful herein. "Polysaccharides"refer to gelling agents which contain a backbone of repeating sugar(i.e., carbohydrate) units. Nonlimiting examples of polysaccharidegelling agents include those selected from the group consisting ofcellulose, carboxymethyl hydroxyethylcellulose, cellulose acetatepropionate carboxylate, hydroxyethylcellulose, hydroxyethylethylcellulose, hydroxypropylcellulose, hydroxypropyl methylcellulose,methyl hydroxyethylcellulose, microcrystalline cellulose, sodiumcellulose sulfate, and mixtures thereof. Also useful herein are thealkyl substituted celluloses. In these polymers, the hydroxy groups ofthe cellulose polymer is hydroxyalkylated (preferably hydroxyethylatedor hydroxypropylated) to form a hydroxyalkylated cellulose which is thenfurther modified with a C₁₀ -C₃₀ straight chain or branched chain alkylgroup through an ether linkage. Typically these polymers are ethers ofC₁₀ -C₃₀ straight or branched chain alcohols withhydroxyalkylcelluloses. Examples of alkyl groups useful herein includethose selected from the group consisting of stearyl, isostearyl, lauryl,myristyl, cetyl, isocetyl, cocoyl (i.e. alkyl groups derived from thealcohols of coconut oil), palmityl, oleyl, linoleyl, linolenyl,ricinoleyl, behenyl, and mixtures thereof. Preferred among the alkylhydroxyalkyl cellulose ethers is the material given the CTFA designationcetyl hydroxyethylcellulose, which is the ether of cetyl alcohol andhydroxyethylcellulose. This material is sold under the tradenameNatrosol® CS Plus from Aqualon Corporation (Wilmington, Del.).

Other useful polysaccharides include scleroglucans comprising a linearchain of (1-3) linked glucose units with a (1-6) linked glucose everythree units, a commercially available example of which is Clearogel™CS11 from Michel Mercier Products Inc. (Mountainside, N.J.).

(v) Gums

Other thickening and gelling agents useful herein include materialswhich are primarily derived from natural sources. Nonlimiting examplesof these gelling agent gums include materials selected from the groupconsisting of acacia, agar, algin, alginic acid, ammonium alginate,amylopectin, calcium alginate, calcium carrageenan, carnitine,carrageenan, dextrin, gelatin, gellan gum, guar gum, guarhydroxypropyltrimonium chloride, hectorite, hyaluroinic acid, hydratedsilica, hydroxypropyl chitosan, hydroxypropyl guar, karaya gum, kelp,locust bean gum, natto gum, potassium alginate, potassium carrageenan,propylene glycol alginate, sclerotium gum, sodium carboyxmethyl dextran,sodium carrageenan, tragacanth gum, xanthan gum, and mixtures thereof.

Preferred compositions of the present invention include a thickeningagent selected from the group consisting of carboxylic acid polymers,crosslinked polyacrylate polymers, polyacrylamide polymers, and mixturesthereof, more preferably selected from the group consisting ofcarboxylic acid polymers, polyacrylamide polymers, and mixtures thereof.

g) Humectants, Moisturizers, and Skin Conditioners

Preferred compositions optionally comprise one or more humectants,moisturizers, or skin conditioners. A variety of these materials can beemployed and each can be present at a level of from about 0.01% to about20%, more preferably from about 0.1% to about 10%, and most preferablyfrom about 0.5% to about 7%. These materials include, but are notlimited to, guanidine; glycolic acid and glycolate salts (e.g. ammoniumand quaternary alkyl ammonium); salicylic acid; lactic acid and lactatesalts (e.g., ammonium and quaternary alkyl ammonium); aloe vera in anyof its variety of forms (e.g., aloe vera gel); polyhydroxy alcohols suchas sorbitol, glycerol, hexanetriol, propylene glycol, butylene glycol,hexylene glycol and the like; polyethylene glycols; sugars and starches;sugar and starch derivatives (e.g., alkoxylated glucose); hyaluronicacid; lactamide monoethanolamine; acetamide monoethanolamine; andmixtures thereof. Also useful herein are the propoxylated glycerolsdescribed in U.S. Pat. No. 4,976,953, to Orr et al, issued Dec. 11,1990.

Also useful are various C₁ -C₃₀ monoesters and polyesters of sugars andrelated materials. These esters are derived from a sugar or polyolmoiety and one or more carboxylic acid moieties. Such ester materialsare further described in, U.S. Pat. No. 2,831,854, U.S. Pat. No.4,005,196, to Jandacek, issued Jan. 25, 1977; U.S. Pat. No. 4,005,195,to Jandacek, issued Jan. 25, 1977, U.S. Pat. No. 5,306,516, to Letton etal, issued Apr. 26, 1994; U.S. Pat. No. 5,306,515, to Letton et al,issued Apr. 26, 1994; U.S. Pat. No. 5,305,514, to Letton et al, issuedApr. 26, 1994; U.S. Pat. No. 4,797,300, to Jandacek et al, issued Jan.10, 1989; U.S. Pat. No. 3,963,699, to Rizzi et al, issued Jun. 15, 1976;U.S. Pat. No. 4,518,772, to Volpenhein, issued May 21, 1985; and U.S.Pat. No. 4,517,360, to Volpenhein, issued May 21, 1985.

h) Emulsifiers

The compositions of the present invention can comprise one or moreemulsifiers, e.g., to reduce the interfacial tension between phases andimprove the formulation and stability of an emulsion. Suitableemulsifiers include a wide variety of nonionic, cationic, anionic, andzwitterionic emulsifiers. See McCutcheon's, Detergents and Emulsifiers,North American Edition (1986), published by Allured PublishingCorporation; U.S. Pat. No. 5,011,681 issued to Ciotti et al on Apr. 30,1991; U.S. Pat. No. 4,421,769 issued to Dixon et al on Dec. 20, 1983;and U.S. Pat. No. 3,755,560 issued to Dickert et al on Aug. 28, 1973.

Suitable emulsifier types include esters of glycerin, esters ofpropylene glycol, fatty acid esters of polyethylene glycol, fatty acidesters of polypropylene glycol, esters of sorbitol, esters of sorbitananhydrides, carboxylic acid copolymers, esters and ethers of glucose,ethoxylated ethers, ethoxylated alcohols, alkyl phosphates,polyoxyethylene fatty ether phosphates, fatty acid amides, acyllactylates, soaps and mixtures thereof.

Suitable emulsifiers include, but are not limited to, TEA stearate, DEAoleth-3 phosphate, polyethylene glycol 20 sorbitan monolaurate(polysorbate 20), polyethylene glycol 5 soya sterol, steareth-2,steareth-20, steareth-21, ceteareth-20, PPG-2 methyl glucose etherdistearate, ceteth-10, polysorbate 80, cetyl phosphate, potassium cetylphosphate, diethanolamine cetyl phosphate, polysorbate 60, glycerylstearate, PEG-100 stearate, and mixtures thereof. Preferred emulsifiersare steareth-2, steareth-21, TEA stearate, diethanolamine cetylphosphate, potassium cetyl phosphate, and mixtures thereof. Theemulsifier can be used individually or as a mixture of two or more andcomprises from about 0.1% to about 10%, more preferably from about 0.15%to about 7%, and most preferably from about 0.25% to about 5% of thecompositions of the present invention.

Methods For Providing Protection From UV Radiation

The compositions of the present invention are suitable for providingprotection against the harmful effects of ultraviolet radiation,preferably in personal care products. More preferably, the compositionsof the present invention are suitable for use as sunscreens to provideprotection to human skin from the harmful effects of UV radiation whichinclude, but are not limited to, sunburn and premature aging of theskin. The present invention therefore also further relates to methods ofprotecting human skin from the harmful effects of UV radiation. Suchmethods generally involve attenuating or reducing the amount of UVradiation which reaches the skin's surface. To protect the skin from UVradiation, a safe and effective (photoprotective) amount of thecomposition is topically applied to the skin. "Topical application"refers to application of the present compositions by spreading,spraying, etc. onto the surface of the skin. The exact amount appliedmay vary depending on the level of UV protection desired. From about 0.5mg of composition per cm² of skin to about 25 mg of composition per cm²of skin are typically applied.

EXAMPLES

The following examples further describe and demonstrate embodimentswithin the scope of the present invention. The examples are given solelyfor the purpose of illustration and are not to be construed aslimitations on the present invention, as many variations thereof arepossible without departing from the spirit and scope of the invention.

The following sunscreen products are representative of the presentinvention.

    ______________________________________                                        Example          I       II      III   IV                                       Component WT % WT % WT % WT %                                               ______________________________________                                        Water            QS 100  QS 100  QS 100                                                                              QS 100                                   Carbomer 980 --  -- 0.50 0.50                                                 Carbomer 954 0.20 0.20 -- --                                                  Acrylates/C.sub.10-30 Alkyl Acrylate.sup.1 0.10 0.10 0.10 1.10                Disodium EDTA 0.05 0.05 0.05 0.05                                             Methyl Paraben 0.25 0.25 0.25 0.25                                            Glycerin 4.00 4.00 7.00 7.00                                                  Octyl methoxycinnamate -- 3.00 -- --                                          Octyl Salicylate -- -- 2.00 --                                                Isopropyl myristate 6.00 6.00 6.00 6.00                                       Propyl Paraben 0.15 0.15 0.15 0.15                                            1-Acetonaphthone 0.50 1.65 -- --                                              1-Naphthaldehyde -- -- 0.25 1.00                                              4-t-Butyl-4'methoxydibenzoyl- 2.00 3.00 1.00 2.00                             methane                                                                       DEA Oleth-3 Phosphate 0.75 0.75 0.75 0.75                                     Stearic Acid 1.00 1.00 1.00 1.00                                              Cetyl Alcohol 1.00 1.00 1.00 1.00                                             Cetyl Palmitate 0.50 0.50 0.50 0.50                                           Triethanolamine 0.70 0.70 1.5  1.5                                          ______________________________________                                         .sup.1 Available as Pemulen TR1 from B. F. Goodrich                      

Prepare a water phase by combining the water, Carbomer 980 or Carbomer954, acrylate copolymer, disodium EDTA, methyl paraben, and glycerin inan appropriate vessel with mixing and heating to 75° C. Prepare the oilphase by combining the octyl methoxycinnamate, octyl salicylate,isopropyl myristate, propyl paraben, 1-acetonaphthone, 1-naphthaldehyde,4-t-butyl-4'-methoxydibenzoylmethane, DEA oleth-3-phosphate, stearicacid, cetyl alcohol, and cetyl palmitate in a separate vessel withmixing and heating to 75° C. Next, mix the oil phase into the waterphase with shearing to form an emulsion. Cool the emulsion with shearingto 60° C. and add the triethanolamine. Slowly stir the emulsion and coolto 30-35° C. and package as desired.

What is claimed is:
 1. A composition suitable for providing protectionagainst the harmful effects of ultraviolet radiation, said compositioncomprising:a) a safe and effective amount of a UVA-absorbingdibenzoylmethane sunscreen active; b) a safe and effective amount of anaphthalene derivative having the formula ##STR8## wherein R is in the 1or 2 position and is independently selected from the group consisting ofCHO, COOH, COR' wherein R' is a C₁ -C₃₀ straight or branched alkyl or anaryl, and wherein said naphthalene derivative has a triplet energy stateof from about 56 kcal/mol to about 59.5 kcal/mol; and c) a suitablecarrier.
 2. The composition of claim 1 wherein the naphthalenederivative is selected from the group consisting of 1-naphthaldehyde,2-naphthaldehyde, 2-acetonaphthone, 1-naphthoic acid, 1-acetonaphthone,and mixtures thereof.
 3. The composition of claim 2 wherein thenaphthalene derivative is selected from the group consisting of1-naphthaldehyde, 1-acetonaphthone, and mixtures thereof.
 4. Thecomposition of claim 3 wherein the naphthalene derivative is1-acetonaphthone.
 5. The composition of claim 1 wherein theUVA-absorbing dibenzoylmethane sunscreen active is selected from thegroup consisting of 2-methyldibenzoylmethane, 4-methyldibenzoylmethane,4-isopropyldibenzoylmethane, 4-tert-butyldibenzoylmethane,2,4-dimethyldibenzoylmethane, 2,5-dimethyldibenzoylmethane,4,4'-diisopropylbenzoylmethane, 4-tert-butyl-4'-methoxydibenzoylmethane,2-methyl-5-isopropyl-4'-methoxydibenzoylmethane,2-methyl-5-tert-butyl-4'-methoxydibenzoylmethane,2,4-dimethyl-4'-methoxydibenzoylmethane,2,6-dimethyl-4'tert-butyl-4'methoxydibenzoylmethane, and mixturesthereof.
 6. The composition of claim 1 wherein the UVA-absorbingdibenzoylmethane sunscreen active is selected from the group consistingof 4-tert-butyl-4'-methoxydibenzoylmethane, isopropyldibenzoylmethane,and mixtures thereof.
 7. The composition of claim 1 wherein theUVA-absorbing dibenzoylmethane sunscreen active is4-tert-butyl-4'-methoxydibenzoylmethane.
 8. The composition of claim 1wherein the composition comprises from about 0.01% to about 30%, byweight of the composition, of the UVA-absorbing dibenzoylmethanesunscreen active.
 9. The composition of claim 1 wherein the compositioncomprises from about 0.1% to about 6%, by weight of the composition, ofthe UVA-absorbing dibenzoylmethane sunscreen active.
 10. The compositionof claim 1 wherein the composition comprises from about 1% to about 3%,by weight of the composition, of the UVA-absorbing dibenzoylmethanesunscreen active.
 11. The composition of claim 1 wherein the mole ratioof the UVA-absorbing dibenzoylmethane sunscreen active to thenaphthalene derivative is from about 8:1 to about 1:1.
 12. Thecomposition of claim 11 wherein the composition comprises from about0.01% to about 30%, by weight of the composition, of the UVA-absorbingdibenzoylmethane sunscreen active and wherein the napthalene derivativeis selected from the group consisting of 1-naphthaldehyde,2-naphthaldehyde, 2-acetonaphthone, 1-naphthoic acid, 1-acetonaphthone,and mixtures thereof.
 13. The composition of claim 12 wherein theUVA-absorbing dibenzoylmethane sunscreen active is selected from thegroup consisting of 2-methyldibenzoylmethane, 4-methyldibenzoylmethane,4-isopropyldibenzoylmethane, 4-tert-butyldibenzoylmethane,2,4-dimethyldibenzoylmethane, 2,5-dimethyldibenzoylmethane,4,4'-diisopropylbenzoylmethane, 4-tert-butyl-4'-methoxydibenzoylmethane,2-methyl-5-isopropyl-4'-methoxydibenzoylmethane,2-methyl-5-tert-butyl-4'-methoxydibenzoylmethane,2,4-dimethyl-4'-methoxydibenzoylmethane,2,6-dimethyl-4'tert-butyl-4'methoxydibenzoylmethane, and mixturesthereof.
 14. The composition of claim 11 wherein the mole ratio of theUVA-absorbing dibenzoylmethane sunscreen active to the naphthalenederivative is from about 4:1 to about 1:1.
 15. The composition of claim14 wherein the mole ratio of the UVA-absorbing dibenzoylmethanesunscreen active to the naphthalene derivative is from about 2:1 toabout 1:1.
 16. The composition of claim 15 wherein the compositioncomprises from about 0.1% to about 6%, by weight of the composition, ofthe UVA-absorbing dibenzoylmethane sunscreen active and wherein thenapthalene derivative is selected from the group consisting of1-naphthaldehyde, 1-acetonaphthone, and mixtures thereof.
 17. Thecomposition of claim 16 wherein the UVA-absorbing dibenzoylmethanesunscreen active is selected from the group consisting of4-tert-butyl4'-methoxydibenzoylmethane, isopropyldibenzoylmethane, andmixtures thereof.
 18. A method for providing protection against theharmful effects of ultraviolet radiation to skin, said method comprisingapplying a safe and effective amount of the composition of claim 1 toskin.
 19. A composition suitable for providing protection against theharmful effects of ultraviolet radiation, said composition comprising:a)an effective amount of a UVA-absorbing dibenzoylmethane sunscreenactive; b) an effective amount of a naphthalene derivative having theformula ##STR9## wherein R is in the 1 or 2 position and isindependently selected from the group consisting of CHO, COOH, COR'wherein R' is a C₁ -C₃₀ straight or branched alkyl or an aryl, andwherein said naphthalene derivative has a triplet energy state of fromabout 56 kcal/mol to about 59.5 kcal/mol; and c) a suitable carrier. 20.A method of stabilizing a UVA-absorbing dibenzoylmethane sunscreenactive, said method comprising combining an effective amount of aUVA-absorbing dibenzoylmethane sunscreen active with an effective amountof a naphthalene derivative having the formula ##STR10## wherein R is inthe 1 or 2 position and is independently selected from the groupconsisting of CHO, COOH, COR wherein R' is a C₁ -C₃₀ straight orbranched alkyl or an aryl, and wherein said naphthalene derivative has atriplet energy state of from about 56 kcal/mol to about 59.5 kcal/mol.